IDE-SD adapter question

[W2HX]

Could it be related to the fact that it is a 2GB SD card and I believe IDE controllers of that day could only address something like 500MB?

Should I consider trying to partition the SD card into a 500MB partition?

Eugene


From: Richard Cini <rich.cini at verizon.net>
Sent: Friday, June 26, 2020 6:08 PM
To: W2HX <w2hx at w2hx.com>; General Discussion: On-Topic Posts <cctech at classiccmp.org>
Subject: Re: IDE-SD adapter question

Off hand, I wonder if the 486 doesn't support logical block addressing in the BIOS (or its not enabled). Modern machines (and those of a Windows 95 vintage) do not use CHS addressing (cylinder, head, sector) any longer.

SD cards usually don't return Sector errors because of the dynamic remapping the firmware does.

Rich

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From: cctech <cctech-bounces at classiccmp.org<mailto:cctech-bounces at classiccmp.org>> on behalf of W2HX via cctech <cctech at classiccmp.org<mailto:cctech at classiccmp.org>>
Sent: Friday, June 26, 2020 5:39:57 PM
To: cctech at classiccmp.org<mailto:cctech at classiccmp.org> <cctech at classiccmp.org<mailto:cctech at classiccmp.org>>
Subject: IDE-SD adapter question

Hi all,

Thanks for previous help on this project. I am working on an old 486 computer and I have replaced a 40 pin IDE hard drive with this SD adapter...
https://www.amazon.com/gp/product/B07G29TZPS/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

In general it seems to mostly be working. I can see a directory listing of several thousands files located on a 2GB SD card from yesteryear. The SD card was new when I installed it (has been in my possession for years).

However, I do get errors "sector not found" and if I A)bort I get INT 24 error.  I am trying to get windows 95 installed and this is certainly preventing that.

In the BIOS settings I have the hard drive set as "USER" and these parameters:
CY:[1024] HD:[16] ST:[63] LZ:[1024] WP:[0]
These were the parameters in use while I was still using the actual hard drive.

Question 1: Now that I am using an SD card instead of an IDE drive, what, if anything, should I be doing with these BIOS parameters?
Question 2: The BIOS has an option to format the hard drive. Should I format the SD card using this facility?

I did not explicitly put a filesystem on that SD card. I placed it in a windows 7 machine, it was recognized, and I began copying files to it. I then place the SD card into the 486 machine where I saw the sector not found errors.

Any advice how to proceed?
Thanks
Eugene